However, negotiations between Jamie Heaslip’s representatives and the IRFU have not yet reached such an advanced stage and there is still a possibility that the Leinster forward may yet reject the Union’s overtures.

Heaslip last week declared that the IRFU had to “value the player” after indicating that he had received numerous offers from overseas to leave Leinster.

However, the IRFU are committed to working within strict financial guidelines and, having secured Sexton’s signature, they may be willing to allow Heaslip to take up one of his offers.

Signing both players could set back the Union close to €1m per annum once bonuses and appearance fees are taken into account and the IRFU may decide that Sexton’s signature is more vital than Heaslip’s.

Sean O’Brien has proved a readymade stand-in for Leinster and will do so for Ireland in Italy this weekend, while the IRFU would still be able to call up Heaslip for international matches.

Sources close to both sides insist there is a determination to do a deal that keeps the player in Ireland, but although Sexton’s deal may be announced next week, there is little certainty that such a timetable can be achieved with regard to Heaslip